Patent GB-1007489-A (GB)
Title: Dehydrogenation process
IPC: C07C15/00
Filed: 1961-08-29
Abstract: The dehydrogenation of organic compounds containing the group <FORM:1007489/C4-C5/1> is effected in the presence of oxygen and a halogen or halogen-liberating material, the amount of oxygen being at least 1/4 mol of organic compound and greater than 1.25 mol per atom of halogen, and a catalyst comprising an oxide or hydroxide of a Group IA or IIA metal and another inorganic metal compound or a metal.  The organic compound may be an alkane, alkene, alkyl aromatic compound or cycloalkane.  Suitable halogen-liberating materials are hydrogen halides, alkyl halides and ammonium halides; the mol ratio of halogen to organic compound may be 0.001-1: 1.  Oxygen is used in amounts of 0.25-5 mols per mol of organic compound and 1.25-4 mols per atom of halogen.  The partial pressure of organic compound is preferably maintained below 1/2 atmosphere when the total pressure is less than one atmosphere and below half the total pressure when this is one atmosphere or more, e.g. by using a diluent such as steam in an amount of 2-40 mols per mol of compound.  The temperature may be 400-850 DEG  C., the space velocity 0.25-3 v./v./hr. and the contact time 0.01-2 seconds.  The alkali or alkaline earth metal oxide or hydroxide may form 0.1-50% of the catalyst, the remainder being a salt, oxide or hydroxide of any metal, many being specified. The examples illustrate the following conversions: butene-2 to butadiene; ethylbenzene to styrene; isobutane to isobutene; 2-methylbutene-2 to isoprene; ethane to ethylene; propane to propylene; ethylcyclohexane to styrene; cyclohexane to benzene; isopropyl benzene to alpha-methylstyrene; and butane to butadiene. Specifications 977,146, 983,915, 988,619 and 992,115 are referred to.ALSO:The dehydrogenation of organic compounds containing the group <FORM:1007489/C2/1> is effected in the presence of oxygen and a halogen or halogen-liberating material, the amount of oxygen being at least 1/4 mol. per mol. of organic compound and greater than 1.25 mol. per atom of halogen, and a catalyst comprising an oxide or hydroxide of a Group Ia or IIa metal and another inorganic metal compound or a metal.  The organic compound may be an alkyl halide, ether, ester, aldehyde, ketone, acid, substituted alkyl aromatic compound, e.g. an alkyl chlorobenzene, alkyl heterocyclic compound, e.g. ethyl pyridine or cyanoalkane. Suitable halogen-liberating materials are hydrogen halides, alkyl halides and ammonium halides; the mol. ratio of halogen to organic compound may be 0.001-1 : 1.  Oxygen is used in amounts of 0.25-5 mols. per mol. of organic compound and 1.25-4 mols. per atom of halogen.  The partial pressure of organic compound is preferably maintained below 1/2 atmosphere when the total pressure is less than one atmosphere and below half the total pressure when this is one atmosphere or more by using a diluent such as steam in an amount of 2-40 mols. per mol. of compound. The temperature may be 400-850 DEG  C., the space velocity 0.25-3 v./v./hr. and the contact time 0.01-2 seconds.  The alkali or alkaline earth metal oxide or hydroxide may form 0.1-50% of the catalyst, the remainder being a salt, oxide or hydroxide of any metal, many being specified.  The examples illustrate the following conversions: propionitrile to acrylonitrile; ethyl chloride to vinyl chloride; methyl isopropyl ketone to methyl isopropenyl ketone; 2 - chlorobutene - 2 to chloroprene and propionaldehyde to acrolein.  Specifications 977,146, 983,915, 988,619 and 992,115 are referred to.